Composite molded snowboard with metal edges

ABSTRACT

Products of and methods for producing complex shapes of composite molded articles, including snowboards, that meet or exceed the aesthetic, cost and performance requirements expected of similar non-molded composite articles. The injection molded or co-injection molded snowboard comprises a top surface and a bottom surface shaped to provide a center portion, at least one tip or tail portion and edges along the sides of the center portion, wherein the bottom surface is a substantially smooth continuous surface, the center portion is cambered away from the top surface and contains metal edges along the sides of the bottom surface center portion, the tip or tail portions are curved away from the bottom surface of the snowboard and the top surface contains binding mounts or screw threads flush mounted to secure bindings.

FIELD OF THE INVENTION

The present invention relates generally to products of and methods forproducing complex shapes of composite molded articles, including asnowboard with metal edges, by the process of co-injection molding.

BACKGROUND OF THE INVENTION

None of the following is admitted to be prior art to the presentinvention.

Injection molded, including co-injection molded, articles could bevastly improved if there was a method for producing complex shapes ofcomposite molded articles, in a single molding operation; thusoptimizing the value of injection molding and maintaining or improvingthe characteristics expected of similar non-molded composite articles.For example, a problem that has long plagued the art of snowboardmanufacturing has been the time and cost associated with manufacturingmultiple layer laminated snowboards with metal edges to meet specificaesthetic and performance requirements. Injection molding has beensought after as a means of reducing such time and costs ofmanufacturing, but to date, has been unable to achieve all of theaesthetic, cost and performance attributes the public has come to expectof modern laminated snowboards. What is needed is a method for producingcomplex shapes of composite molded articles that meet or exceed theaesthetic and performance requirements expected of similar non-moldedcomposite articles, preferably at reduced costs.

Injection Molding

Injection molding is where thermoplastic polymers are gravity-fed from ahopper into a barrel, melted by a reciprocating screw and/or electricheat and are propelled forward by a ram (piston, plunger) or the screw(used as a plunger) into mating steel or aluminum molds, which arecooled to below the heat-distortion temperature of the resin. Theinjected plastic material contracts as it cools (mold shrinkage) andshrinks. When cool enough to retain its shape, the plastic part isejected from the mold.

Typically, good part design requires adequate taper (draft) of sidewalls, radii at inside corners, minimal variations in wallcross-sections, use of ribs 60% or less of outer wall thickness forstiffness, strength and minimal sink marks. Thermosetting polymers canalso be injection-molded. For these materials, the barrels on theinjection-molding machine are heated by hot water to a point safelybelow cross-linking temperature; the polymer is then propelled by ram orscrew feed into heated molds. After they cure, the parts can be ejectedwhile still hot because they have already thermally set or cross-linked.

Injection molding of polymers has revolutionized many industries. Mostproducts today contain some form of plastic molded parts in them orconsist entirely of plastic molded parts. Such products include toys,automobile parts, computer covers, phones, liquid containers and many,many other articles, too numerous to recite. However, modern moldingoperations have not been able to produce complex shapes of compositemolded articles, in a single molding operation, that meet or exceed theaesthetic and performance requirements expected of similar non-moldedcomposite articles. For certain products, aesthetic or performancerequirements dictate that non-molded components, such as metals orceramics, be utilized. However, incorporating polymer materials andnon-molding materials in the single molding step has not been able toachieve the complex geometries required of some products, includingmolded snowboards with metal edges. For example, round washers have beenembedded into molded parts as the base legs of appliances, computers andother similar articles to lift them off of the floor. However, suchcomponents do not require the metal and molded polymer to retain a bent,curved or complex shape whereby the shape of the article presents forcesthat separate the polymer and non-molded component.

Co-Injection Molding

Co-injection molding takes advantage of a characteristic of injectionmolding called fountain flow. That is, as the cavity is filled, theplastic at the melt front moves from the center line of the stream tothe cavity walls. Because the walls are below the transition temperature(freeze temperature) of the melt, the material that touches the wallscools rapidly and freezes in place. This provides insulating layers oneach wall, through which new melt makes its way to the melt front.

Sequential co-injection processes have two barrels and one nozzle in aninjection molding machine. The skin polymer is injected into the moldfirst, then the core polymer is injected. The skin polymer is thematerial that is expected to be deposited on the cavity wall over theentire surface of the part. The core polymer displaces the skin polymerat the hot core, pushing it to fill the rest of the cavity. The endproduct is a sandwich-like structure, with the core polymer in themiddle and the skin polymer on the surfaces of the part.

As two materials are processed, two hopper/screw/barrel assemblies arerequired for co-injection. A special co-injection nozzle allows theoperator to alternate between the two materials with the speed, timingand accuracy necessary to optimize the co-injection application.

The advantages of this process are: the combination of two materialproperties into one part, and the maximization of the overallperformance/cost ratio. One good example of co-injection is the use ofpolymer re-grind as the core material, while maintaining surface finishquality by using virgin polymer as the skin material. Other applicationsinclude using thermally more stable polymer as the core material toincrease the thermal resistance of a part, or using a high melt-flowindex polymer as the core material, to reduce the overall clamp force.Still other applications include using a core material that is lighterand exhibits more flexibility than the skin material to combine strengthand flexibility to the desired part, while keeping the weight down. Onecombination may include a fiberglass loaded core material to provide astructural component to the part and a different skin material tomaintain a smooth, consistent surface.

Numerous articles on the co-injection process have been authored. Somearticles include, Co-Injection Molding '95: Market Outlook, by Thomas W.Betts of Battenfeld of America, Inc; Molded-In Shielding Using theCoinjection Process, by Thomas W. Nash and Ralph J. McDonald, IBMApplication Business Systems, Rochester, Minn. 55901; CoinjectionMolding with Automotive Polyolefins, by Bruce R. Denison, D & S PlasticsInternational; Recycling—Why Not Use Co-Injection Molding?, by JosephMcRoskey of Co-Mack Technology, Inc. and Thomas W. Nash of Thomas W.Nash & Associates; and Co-Injection Molding: Current Applications, byJoseph McRoskey of Co-Mack Technology, Inc. (May 31-Jun. 2, 1998). Theforegoing articles are incorporated herein by reference, including anydrawings.

Injection and co-injection molding operations that incorporateadditional non-molded components, such as metal edges, compriseadditional technical hurdles to overcome, especially when suchnon-molded components are incorporated into a single molding operationstep. Such hurdles include the need to adjust for shrinkage of thepolymer as it cools in the mold; securing the non-molded componentswithin the mold and eliminating or minimizing surface lines frominserting components into the mold. Previous attempts to address suchtechnical matters have not succeeded in producing a snowboard that meetthe expectations of an industry dominated by laminated snowboards.

Some molded snowboards comprise a low-grade plastic material with metaledges. Such snowboards lack smooth continuous curves and surfaces, lacka proper camber, tend to warp, and contain exposed metal points. Suchirregularities may be caused by inserting plugs into holes made forbinding fasteners, methods of holding the edges in place during themolding process and by the shrinkage of inconsistent material densities.Other injection molded snowboards leave space for metal edges andbinding fasteners to be inserted and glued to the injection moldedsection of the snowboard as a secondary process. Such additional processsteps are time consuming and expensive and produce a snowboard thatsuffers from some of the same delamination issues as traditionallaminated snowboards.

Laminated Snowboards

Most modern snowboards are produced by laminating several materialstogether. Such snowboards are produced by companies such as RideSnowboards, K2, Saloman, Burton and Morrow, to name a few. Examples ofmodern laminated snowboards can be found on web sites operated by thesecompanies, including http://www.ridesnowboards.com,http://www.burton.com, http://www.k2snowboards.com,http://www.salomonsports.com/northamerica/snowboarding/connect/pub.html,and http://www.morrowsnowboards.com. This list is not an exhaustive listas there are hundreds of snowboard companies in business, owning to thepopularity of the sport. Further examples may be found in U.S. Pat. Nos.5,769,445; 5,782,482; 5,823,562; 5,851,331; 5,855,389; and 5,871,224.

The modern snowboard laminating technique consists of sandwichingmultiple layers together with resins and industrial adhesives. Suchlayers typically include a wood or foam core, fiber reinforcement layer,thermoplastic layers, metal edge material, base material and a monocoqueenvelope. Other features may include the use of reinforcing materials inthe end portions of the snowboard as an attempt to prevent delamination.Graphics may be applied below the top surface or monocoque envelope orto the top of it. In the sandwiched layers a set of screw threads orbinding fasteners are inserted for securing bindings to the snowboard.Laminated boards have set the standard for the snowboard industry interms of aesthetics and performance. The boards are strong enough towithstand the pressures applied by snowboard riders and flexible enoughto absorb the shocks applied through maneuvers.

Notwithstanding the above, laminated boards experience severaldisadvantages. The laminated layers are held together by adhesives. Thelayers separate over prolonged use. Moreover, ice and snow can penetrateinto the cracks between adhered layers and destroy the structuralintegrity of the snowboards, thereby delaminating the layers and themetal edges. The inserted screw threads for securing bindings depend onthe strength of the adhesives. The screw threads may sometimes loosenand spin within the boards. As well, modern laminating techniques aretime consuming, environmentally harmful and expensive to operate,requiring hours of labor for adhering layers, inserting screw threadsand shaping the product.

What is needed is a method for producing complex shapes of compositemolded articles, including snowboards, that meet or exceed the aestheticand performance requirements expected of similar non-molded compositearticles, preferably at reduced costs and using recyclable materials.

SUMMARY OF THE INVENTION

The present invention comprises products of and methods for producingcomplex shapes of composite molded articles, including snowboards, thatmeet or exceed the aesthetic, cost and performance requirements expectedof similar non-molded composite articles. The injection molded orco-injection molded snowboard comprises a top surface and a bottomsurface shaped to provide a center portion, at least one tip or tailportion and edges along the sides of the center portion, wherein thebottom surface is a substantially smooth continuous surface, the centerportion is cambered away from the top surface and contains metal edgesalong the sides of the bottom surface center portion, the tip or tailportions are curved away from the bottom surface of the snowboard andthe top surface contains binding mounts or screw threads flush mountedto secure bindings.

A preferred method of constructing a snowboard comprises co-injectionmolding, utilizing a skin polymer with a smooth finish for exteriorportions of the snowboard and a core polymer that is lighter,structurally stronger and potentially cheaper than the skin polymer forthe interior of the snowboard. A mold cavity is designed for the desiredshape of the snowboard. In addition to providing for the shape of thesnowboard, the mold cavity is designed to accommodate inserts for sidemetal edges and clips to secure such edges, if necessary, and insertsfor top, flush mounted binding mounts or screw threads as well as theclips to secure such mounts. An additional set of metal components maybe embedded within the top surface of the snowboard to compensate forwarping away from the bottom metal edges due to the polymer shrink rate.The mold cavity must be designed to accommodate inserts for securingsuch metal components if such components are utilized.

As the polymer in the mold cools, it shrinks and the shrinkage ratedepends on the polymer material selected. The metal edge material thatis secured into the molten polymer does not shrink and therefore theshrinking polymer tends to “pull” the embedded metal component with it.This shrinkage and pulling action warps or bends the metal edge. Thebottom surface metal edges contour to the final cure form of themajority polymer component, which for a snowboard is upward toward thetop surface of the snowboard.

Several methods to adjust for the shrinkage rate of a particular polymermaterial may be employed. One method is to adjust the curvature of thesnowboard mold cavity so that the warping will provide the desiredcurvature when cooling is completed. Another method is to adjust thecomposition of the polymer material, through additives or glass loading,to control the warping to provide the desired curvature when cooling iscompleted. Since the metal edges along the bottom surface of thesnowboard are designed to be at a set camber after cooling, the exactadjustment necessary to achieve the desired camber after coolinginvolves an iterative process depending on the polymer materialselection.

Another method to adjust for the shrinkage rate of a particular polymermaterial is to embed additional metal components similar to the bottomedge materials, into the top surface of the mold. Therefore, as thepolymer material cools and shrinks, it will pull away from both the topand bottom portions in substantially equal proportions, therebycounteracting each other and producing the desired shape. Care must betaken to embed the top metal edges into the top surface so that they donot stick out of the top surface and so that they are not embedded sodeep as to have no effect. The preferred depth is in the range of 0.015to 0.060 inches (0.038 to 0.152 cm) for a snowboard that isapproximately 0.5 inches (1.27 cm) thick. Proper placement involves aniterative process depending on the polymer material selection.

The mold cavity is split in two halves, an “A” half and a “B” half, withthe A half representing the top of the snowboard article beingmanufactured and the B half representing the bottom of the snowboardarticle being manufactured. Loaded into each side of the B half is a Bside rail insert comprising a metal rail with locator clips attached tothe metal rails at about 3.5 inches (8.9 centimeters) apart center tocenter from adjacent clips whereby the locator clips are in moldedcavities of the B side rail insert. Loaded into the A half is (i)parallel to, but not flush with, each side of the A half is an A siderail insert comprising a metal rail with locator clips attached to themetal rails at about 3.5 inches (8.9 cm) apart center to center fromadjacent clips whereby the locator clips are in molded cavities of the Aside rail insert and (ii) two A side nut inserts, each nut insertcomprising six (6) nuts secured in place on the nut insert by sixmillimeter (6 mm) screws from the back of the nut insert The distancebetween locator clips depends on the size of the snowboard. The goal isto allow the A side metal rail to “float” a bit within the mold, soproper placement and location of clips is an iterative process dependingon the size of the snowboard. The inserted nuts comprise a base that iswider than the threading such that the wider base is embedded within themolded polymer. In order to resist spinning within the molded part, asdetermined by screw-retention strength standards of binding mounts foralpine skis, in compliance with ASTM Standard Nos. F474-98 and F475-77(1992), the wider base is preferably a polygon or other non-roundedshape such as a hexagon.

The locator clips for the A side rails are designed to be a specificsize in order to embed the top metal rails into the top surface of thesnowboard so that the metal rails do not stick out of the top surfaceand so that the metal rails are not embedded so deep as to have noeffect on the curvature of the board as described above. Properplacement involves an iterative process depending on the polymermaterial selection. A depth change of just five thousandths of an inch(0.005 inches or 0.013 centimeters) causes a difference in the shape ofthe snowboard product.

Once all of the inserts have been located within the A and B sidecavities of the mold, the mold is closed and the co-injection moldingcycle is operated. The mold is then opened and the snowboard is removedfrom the B side of the mold. The locator clips on the B side of the moldbreak off, producing small plastic nubs. The screw threads holding theinserts for the binding nuts are removed. The A side locator clips arecut off and milled down.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an open snowboard mold cavity with inserts in accordancewith the present invention.

FIG. 2a depicts a metal rail and locator clip for the bottom of asnowboard in accordance with the present invention.

FIG. 2b depicts a mold insert incorporating a metal rail with locatorclips for the bottom of a snowboard in accordance with the presentinvention.

FIG. 3a depicts a metal rail and locator clip for the top of a snowboardin accordance with the present invention.

FIG. 3b depicts a mold insert incorporating a metal rail with locatorclips for the top of a snowboard in accordance with the presentinvention.

FIG. 4 depicts a mold insert incorporating a nut with a screw forincorporation into the top of a snowboard in accordance with the presentinvention.

FIG. 5 depicts a cross-sectional view of a closed snowboard mold of thepresent invention.

FIG. 6 depicts a metal rail for the bottom of a snowboard in accordancewith the present invention.

FIG. 7 depicts a snowboard produced in accordance with the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description includes the best presently contemplated modeof carrying out the invention. This description is made for the purposeof illustrating the general principles of the inventions and should notbe taken in a limiting sense.

Injection molded parts, especially snowboards, having curved portionsincorporating non-resin materials such as metal components, requireinnovative methods for incorporating such non-resin components whilemaintaining the required shape for aesthetic and performance purposes.Moreover, ensuring that the final molded product requires minimumprocessing after the molding operation, while incorporating suchnon-resin materials, is a desired benefit of the present invention. Themethods described herein produce snowboards having metal edges, acambered bottom surface, ends curved away from the bottom surface andsmooth finishes at costs and production times lower than conventionallaminating methods.

Definitions

“A” Side and Top Surface

The terms “A side” and “top surface” are used interchangeably throughoutto refer to the top surface of the snowboard product as viewed by atypical snowboard rider. The “A side” is that portion of the mold cavitythat results in the top surface of the final molded snowboard product.

“B” Side and Bottom Surface

The terms “B side” and “bottom surface” are used interchangeablythroughout to refer to the bottom surface of the snowboard product asviewed by a typical snowboard rider. The “B side” is that portion of themold cavity that results in the bottom surface of the final moldedsnowboard product.

Composite Molded Articles and Complex Shapes

The term “composite molded article,” refers to injection or co-injectionmolded parts that comprise an additional non-molded component part, in asingle molding operation step, so that the final article resembles ahomogeneous article. The term “complex shape” refers to a compositemolded article whereby the shape of the article produces forces inherentin the molding operation that tend to separate the polymer andnon-molded component and whereby the separation forces are notcounteracted in the molding operation, but rather, are compensated forand utilized to shape the composite molded article. An example of acomposite molded article of a complex shape includes, but is not limitedto, a plastic molded snowboard comprising metal edges and metal bindingfasteners, where the metal edges maintain a cambered shape. Many moldedarticles that comprise a non-molded component that is not embeddedwithin, surrounded by, or in sufficient quantity to counteract themolding material forces of the molding polymer will fall into thiscategory. Some examples include, but are not limited to, airplane foodtrays with metal edges for fastening, flashlights, boat accessories,sporting goods, toys and many other articles where it is important tomaintain a homogeneous appearance of a complex shaped article.

Co-Injection Molding

The term “co-injection molding” or “co-injected molds” as usedinterchangeable herein, refers to a process of injection molding wherebya skin polymer is injected into the mold first, then the core polymer isinjected within the skin polymer. The skin polymer, surrounding the corepolymer, is the material that is deposited on the cavity wall over theentire surface of the part.

Co-Injection Molded Snowboard

FIG. 1 depicts an open snowboard mold cavity, split in two halves, “A”half or “upper” half cavity 20 and “B” half or “lower” half cavity 10,with cavity 20 representing the top of snowboard article 60 beingmanufactured and cavity 10 representing the bottom of snowboard article60 being manufactured. Snowboard article 60 is shown for illustrationpurposes only. Loaded into each side of cavity 10 is insert 30 (oneshown) comprising a metal rail with locator clips attached to the metalrails (shown in FIG. 2a). Loaded into cavity 20 is (i) insert 40 (oneshown) parallel to, but not flush with, each side of cavity 20,comprising a metal rail with locator clips attached to the metal rails(shown in FIG. 3a) and (ii) two inserts 50 (one shown) comprising six(6) nuts secured in place on insert 50 (shown in FIG. 4). More or lessnuts may be utilized if desired.

FIG. 2a shows metal rail 35 with locator clips 33 attached to metal rail35. Such locator clips 33 are usually placed at about 3.5 inches (8.9centimeters) apart center to center from adjacent clips, along thelength of metal rail 35. FIG. 2b shows metal rail 35, secured by locatorclips 33, attached to insert 30 via locator clips 33 in mold cavities37.

FIG. 3a shows metal rail 45 with locator clips 43 attached to metal rail45. Such locator clips 43 are usually placed at about 3.5 inches (8.9cm) apart center to center from adjacent clips, along the length ofmetal rail 45. FIG. 3b shows metal rail 45, secured by locator clips 43,attached to insert 40 via locator clips 43 in mold cavities.

Locator clips 43 attached to metal rails 45 are designed to be aspecific size in order to embed metal rails 45 into the top surface ofthe snowboard so that metal rails 45 do not stick out of the top surfaceand so that metal rails 45 are not embedded so deep as to have no effecton the curvature of the board. Proper placement involves an iterativeprocess depending on the polymer material selection. A depth change ofjust five thousandths of an inch (0.005 inches or 0.013 centimeters)causes a difference in the shape of the snowboard product. A depth of0.025 inches (0.064 cm) is preferred for a snowboard article having acenter width from top surface to bottom surface of about 0.50 inches(1.27 cm).

FIG. 4 shows six nuts 55 secured by six millimeter (6 mm) screws 53 (oneshown) attached to insert 50 via screws 53 in mold cavities 57. Nuts 55are preferably polygon in shape, such as a hexagon, so that the nuts donot slip in the snowboard, to meet or exceed ASTM Standard No. F474-98.

Referring to FIG. 1, once inserts 30, 40 and 50 have been located withincavities 10 and 20 of the mold, the mold is closed and the co-injectionmolding cycle is operated according to standard co-injection operatingprocedures. FIG. 5 illustrates a cross-section of the closed molddepicting the middle of a snowboard, width wise, oriented so that thetop of the FIG. is the top of the snowboard article being produced inthe mold. FIG. 5 shows inserts 30, 40 and 50; locator clips 33 and 43;metal rails 35 and 45; screws 53 and nuts 55 and a molded snowboard 60.Referring to FIGS. 1 and 5, the mold is then opened by separatingcavities 10 and 20 and snowboard 60 is removed from cavity 10 of themold. As the mold opens and snowboard 60 is removed, locator clips 33and 43 break off, leaving small nipples (not shown) that are latergrinded off for aesthetic purposes. Graphics, top sheet designs ordrawings may be painted or affixed onto the top surface of the snowboardduring the molding process, using in-mold applications, or appliedpost-process to the completed snowboard.

One presently preferred snowboard produced according to the methods ofthe present invention has the dimensions shown in Table 1 below.However, it is to be understood that the methods of the presentinvention are capable of producing a plurality of snowboards and otherarticles differing substantially in shape and dimension.

TABLE 1 Snowboard Dimensions ITEM DIMENSIONS Overall length, end to end,side view 43.791 inches (111.23 cm) Thickness, side view End portions“tip and tail” 0.203 inches (0.52 cm) Center portion 0.500 inches (1.27cm) Camber radius of center portion, side view Bottom surface 250 inches(635 cm) Top surface 250.450 inches (636.14 cm) End portions, tip andtail, side view Radii 6 inches (15.24 cm) Height, bottom to top of endportions 2.25 inches (5.72 cm) Side edge curvature radii, 300 inches(762 cm) top surface view End portion widths, tip and tail, 9 inches(22.86 cm) top surface view Binding mounts/screw threads location, topsurface view From center of board, length wise 5 inches (12.70 cm) Fromcenter of board, width wise 1.5 inches (3.81 cm) Apart from each other,center to center 1 inch (2.54 cm)

Other shapes and sizes contemplated by the present invention include,but are not limited to, sizes of snowboards that are commerciallyavailable, including snowboards that have a length of anywhere from 90centimeters to 170 or 180 centimeters. Such snowboards may be found atTransWorld Snowboarding on-line at http://www.twsnow.com. A sampling ofsizes of commercially available snowboards, located on the “Board Genie99” of the above web site is shown in Table 2.

TABLE 2 Commercially Available Snowboard Dimensions Eff. S/CManufacturer/Model Length Edge Radius Nose Waist Tail Stance Burton:Fluid 59 159 124 901 29.6 25.6 29.6 18-24 Charger 61 161 125 833 29.625.2 29.6 18-24 Motion 62 161.5 126 810 29.5 24.9 29.5 18-24 FL Project62 162 126 847 29.3 24.9 29.3 18-24 Johan 63 163 126 793 29.6 24.9 29.618-24 Fluid 64 164 129 931 30.2 26 30.2 18-24 Joyride: Factory Series158 122 807 29.3 24.9 29.3 18.12-24.5  Factory Series 159 123 875 29.725.3 29.7 18.12-24.5  Premium Series 161 Dir. 161 128 875 29.7 25 29.718.12-24.5  Premium Series 166 Dir. 166 130 899 30.1 25.3 30.118.12-24.5  K2: Eldorado 158 158.2 123.8 820 29.9 25.6 29.9 18.5-26.5Fatbob 161 159.7 125.7 864 31.5 27.1 31.4 18.5-26.5 Electra 162 161.4126.5 815 30 25.4 29.9 18.5-26.5 Brian Savard 161 162.1 127.3 869 29.425.1 29.4 18.5-26.5 Eldorado 163 163 126.6 836 30.2 25.7 30.1 18.5-26.5Dart 165 164 126.4 843 29.5 25 29.5 18.5-26.5 Morrow: Escape 59 159127.1 883 29.8 25.1 29.8 20   Escape Plus 60 160 127.7 883 31.5 26.931.5 20.5 Dimension 62 161 130 863 29.7 24.8 29.5 20.6 Rail 65 162 128.8890 30.1 25.5 30.1 20.5 Master 63 163 131 875 30.1 25.3 30.1 21.5 Escape64 164 131.6 890 30.2 25.5 30.2 20.5 Ride: Timeless 161 125 850 29.825.5 29.8 17-25 Control 163 127 850 30 25.5 30 17-25 Rossignol:Butane/Stokes 158 123 950 30 25.5 30 N/A Strato Wide 159 121 950 30.5 2629.9 18-24 Nomad 160 121 950 28.7 24.8 28.7 N/A Levitation Dualtec 161121 950 29.3 24.8 28.7 18-24 Strato 166 127 ***** 29.8 25.1 29.1 18-24Strato Wide 166 127 ***** 31.2 26.5 30.5 18-24 Salomon: 400 LT FR 159 WB159 125 960 29.7 25.7 29.7 16.92-23.2  500 pro FR 164 164 127 990 29.424.8 29.4 17.32-22   500 pro FR Adv. 165 165 129.5 996 29.6 25.2 29.1 18.5-22.44

All sizes are in centimeters. S/C Radius refers to the side cut radius.The Nose/Waist/Tail dimensions refer to the width of such sections. TheStance refers to the range of distances between the bindings for arider's feet.

Although one embodiment of the present invention is to construct asnowboard as described above, it is to be understood that alternativemethods for securing metal rails may be employed to eliminate the needfor locator clips. Eliminating locator clips will reduce moldpreparation time, material costs and post-mold processing time. Metalrails must be securely fastened to the outer edges of the B side moldcavity to ensure that they are placed along the bottom edges of thecompleted snowboard article. Injection or co-injection involves a highdegree of pressure such that any space between the metal rails and themold cavity will result in polymer material flowing around the metalrails and covering them. One such method is to utilize a rail shape thatworks in conjunction with the pressure of the injected polymer materialso that the flow of the polymer material forces the metal rails furtherinto the edges of the molded cavity. Such a design may work inconjunction with side magnets utilized to initially place and secure themetal rails in place. The metal rails should also contain an irregularshape within the portion that is embedded within the polymer material soas to ensure mechanical interlocking of the metal rail and the polymermaterial. The mechanical interlocking will secure the metal rail in themolded article and prevent separation upon use of the snowboard.

Another method is to utilize a rail shape that extends into the polymermaterial of the snowboard and extends out of the snowboard, to eliminatethe need for locator clips. The portion that extends out of thesnowboard is used to secure the metal rail to the edge and is milled orground off following the molding operation. FIG. 6 shows a metal rail100 made of a hardened metal such as steel. Metal rail 100 has anirregular or scalloped side 110 for embedding into the molding material,an extended portion 120 for securing metal rail 100 along the side edgesof a mold and a cut out notch 125 for easy grinding off of the extendedportion 120 after the molding operation. Once the extended portion 120is ground off, edge 130 becomes the outer edge of the bottom surface ofa molded snowboard made in accordance with the present invention.

FIG. 7 illustrates a snowboard 60 made in accordance with the teachingsof the present invention. Snowboard 60 contains metal rail edges 35 (oneside shown) and binding nuts 55 (two sets of six shown). A cut outportion shows the embedded metal rail 45 within the top portion ofsnowboard 60, just below or sometimes flush with the snowboard surface.

Although a preferred embodiment of the present invention is to constructa snowboard via a co-injection molding operation, it is to be understoodthat other operations may be utilized either alone, sequentially or inconjunction with one another, including, but not limited to, injectionmolding, compression molding, extrusion molding, structural foammolding, rotational molding, thermoforming, blow molding, reactioninjection molding (RIM), gas assisted molding, composites processing,hand lay-up, spray-up, centrifugal casting, matched die molding, resintransfer molding and other operations of similar import.

Two-Step Molding

An example of another molding operation to construct a snowboard is atwo-step molding process, whereby the first step is to mold a snowboardcore that partially extends to the surface of the snowboard product andthat embeds the non-molded components such as the metal rails and thebinding nuts, according to the teachings of the present invention.Thereafter, a second over-molding operation is conducted to create theouter surface of the part and yield a smooth, continuous surface. Theadvantages of this two-step process are the ability to combinedissimilar core and skin materials and the resulting ability to maximizethe characteristics of the core/skin polymer materials. A variation isto design cavities into the first molding operation to secure thenon-molded components into, for the second over-molding operation. Caremust be taken in the design to allow the second molding operation tomechanically interlock at least some portions of the non-moldedcomponents so that delamination of the part does not result.

Polymer materials that may be employed in the practice of the presentinvention include, without limitation, high density polyethylene (HDPE),polypropylene (PP), polyurethane (PU), acetal, surlyn, nylon andacrylonitrile-butadiene-styrene (ABS), among other materials with theproper and necessary characteristics for the particular application.Other suitable polymer materials and processes are contained in theHandbook of Plastic Materials and Technology, John Wiley & Sons, Inc.(New York 1990), incorporated herein by reference. Moreover, any polymermaterial capable of being incorporated into an injection molding orco-injection molding, or other molding operation may be utilized in thepractice of the present invention.

It should be understood, of course, that the foregoing relates only topreferred embodiments of the present invention and that numerousmodifications or alterations may be made therein without departing fromthe spirit and the scope of the invention as set forth in the appendedclaims.

We claim:
 1. A molded snowboard formed by a single molding operationstep into a homogeneous article comprising: a molding material in theform of a top surface of the snowboard and a bottom surface of thesnowboard shaped to provide a center portion, at least one tip or tailportion, right and left edges and edges along the sides of the centerportion, wherein; the bottom surface is a substantially smoothcontinuous surface, the center portion is cambered away from the topsurface and contains metal edges along the sides of the bottom surfacecenter portion, wherein the metal edges comprise substantially less thanten percent (10%) of the bottom surface, the tip or tail portions arecurved away from the bottom surface of the snowboard, and the topsurface contains a plurality of binding mounts or threaded inserts flushmounted to secure bindings, without a binding plate.
 2. The moldedsnowboard of claim 1 wherein the molding material is a polymer.
 3. Themolded snowboard of claim 2 wherein the polymer is selected from thegroup consisting of high density polyethylene (HDPE), polypropylene(PP), polyurethane (PU), acetal, surlyn, nylon,acrylonitrile-butadiene-styrene (ABS), and combinations thereof.
 4. Themolded snowboard of claim 1 wherein the bottom surface metal edges areembedded into and mechanically interlocked with the molding material. 5.The molded snowboard of claim 1 further comprising metal edges embeddedwithin the top surface.
 6. The molded snowboard of claim 5 wherein thetop surface metal edges are embedded to a depth of between 0.015 to0.060 inches (0.038 to 0.152 cm) for a snowboard that is approximately0.5 inches (1.27 cm) thick.
 7. The molded snowboard of claim 6 whereinthe top surface metal edges are embedded to a depth of 0.025 inches(0.064 cm).
 8. The molded snowboard of claim 1 wherein the length of thesnowboard measured between the right edge and the left edge is between90 to 180 centimeters.
 9. The molded snowboard of claim 1 wherein thelength of the snowboard measured between the right edge and the leftedge is about 111 centimeters.
 10. The molded snowboard of claim 1wherein the radius of the bottom surface of the cambered center portionis about 250 inches (635 centimeters).
 11. The molded snowboard of claim1 wherein the radii of the curved tip and tail portions are about 6inches (15.24 centimeters).
 12. The molded snowboard of claim 1 whereinthe thickness of the center portion from the top surface to the bottomsurface is about 0.5 inches (1.27 centimeters).
 13. The molded snowboardof claim 1 wherein the thickness of the tip and tail portions are about0.2 inches (0.51 centimeters).
 14. A molded snowboard formed by a singlemolding operation step into a homogeneous article comprising: a moldingmaterial in the form of a top surface of the snowboard and a bottomsurface of the snowboard shaped to provide a center portion, at leastone tip or tail portion, right and left edges and edges along the sidesof the center portion, wherein; the bottom surface is a substantiallysmooth continuous surface, the center portion is cambered away from thetop surface and contains metal edges along the sides of the bottomsurface center portion, the tip or tail portions are curved away fromthe bottom surface of the snowboard, and the top surface contains aplurality of binding mounts or threaded inserts flush mounted to securebindings, without a binding plate; and wherein separation forces betweenthe molding material and the metal edges are utilized to shape themolded snowboard.